Drying Modeling and Energy Consumption of Air Dried Sheet (ADS) Rubber by Solar and Biomass Energy

Abstract

This research aims were to evaluate drying kinetics model for describing evolution of moisture transfer of air dried sheet (ADS) rubber by using solar and biomass drying, multi-stages solar and biomass drying [2 stages (2S) and 3 stages (3S)] and conventional open-sun (OS) drying. The experiments were carried out under the conditions of ADS rubber drying with temperature of 30-60°C. Initial moisture contents of sample rubber were varied between 20 and 50% dry-basis. The final moisture content for each drying strategies was fixed at 1±0.05% dry-basis. The experimental drying results were mathematical simulated by 7 common non-linear empirical models. The results showed that fresh rubber sheets drying with OS technique took longer drying time than those of solar and biomass drying. And the simulated data using approximation of diffusion model was the best fitting to experimental data of rubber sheet. Effective diffusivity of ADS rubber was also determined using the 2nd Ficks law of diffusion and conclusion was that effectice diffusivity was dependent on drying temperature and was in order of 10-7 m2/s. With various drying strategies, the results showed that specific energy consumption of 3-stages ADS rubber drying had a relatively low compared to the other drying techniques.